Orange roughy oils are oils extracted from Hoplostethus atlanticus (common name: orange roughy), Hoplostethus mediterraneus, Hoplostethus gilchristi, and Hoplostethus intermedius, all of which are bathybic Trachichthyidae fish having a large fat content, and contain a large amount of unsaturated aliphatic alcohol esters of unsaturated fatty acids. Orange roughy oils have less stickiness and a lightweight, smooth texture. There are standards set for ingredients of quasi-drugs of orange roughy oils that are obtained from Hoplostethus atlanticus (orange roughy) (Non-patent Citation 1).
However, traces of the distinctive fish oil smell of orange roughy oil remain even after deodorization treatment (Non-patent Citation 1). Since orange roughy oils contain traces of polyunsaturated fatty acids such as eicosapentaenoic acid and docosahexaenoic acid, the storage stability is low, and the fishy smell becomes stronger with time. These characteristics have been obstacles to use of orange roughy oils as an ingredient of cosmetic products and the like.
There are several reports on studies of using orange roughy oils as an ingredient of cosmetic products. Orange roughy oils were hydrogenated, but the hydrogenation products were in the form of a solid at room temperature and had significantly changed physical properties (Patent Citation 1). There is a report on a process for the production of purified orange roughy oils that retain monounsaturated fatty acid ester and from which only polyunsaturated fatty acid esters, which cause a fishy smell, are removed (Patent Citation 2). In this process, hydrogenation is carried out to a small degree so that only multivalent unsaturated bonds are hydrogenated, and this is followed by treatment with lipase to remove triglyceride components containing a large amount of polyunsaturated fatty acids. However, the resulting purified orange roughy oils do not meet the Japanese Standards of Quasi-drug Ingredients in a saponification value thereof and the like, and they are not usable as a base of external preparations or cosmetic products.    Patent Citation 1: JP H01-53242 B    Patent Citation 2: JP H05-117686 A    Non-patent Citation 1: Japanese Standards of Quasi-drug Ingredients 2006, Yakuji Nippo Limited, published in June 2006, pages 617-618